The present system relates generally to brake control systems and more specifically to a controller for an equalizing reservoir of a rail brake system, which includes a brake pipe controlled by a relay valve in response to pressure in the equalizing reservoir.
Prior rail brake systems have had either fully-pneumatic control of the equalizing reservoir (ER) or electro-pneumatic control of the ER. On systems which use fully-pneumatic ER control, penalty brake applications were created by exhausting a previously pressurized penalty pipe. This caused a subsequent pneumatic exhaust of the ER and brake application. On systems which use electro-pneumatic ER control, penalty brake applications are signaled to the brake system by electrical signals. The ER is then reduced to apply the brakes via electro-pneumatic control. Prior brake systems including ER controllers are illustrated in U.S. Pat. Nos. 6,036,284 and 6,318,811.
The present control system allows electro-pneumatic control of ER but with the capacity to create penalty applications in a purely pneumatic manner. A controller for an ER includes an electro-pneumatic source of pressure or atmosphere responsive to an electrical equalizing pressure control signal and a pilot valve selectively connecting the electro-pneumatic source or atmosphere to the equalizing reservoir in response to pressure in a pilot port of the first pilot valve. A magnetic valve is provided having a first input connected to a second source of pressure, a second input connected to atmosphere and an output connected to the pilot port of the first pilot valve. At least one penalty valve is connected to the pilot input of the first pilot valve and is responsive to a penalty signal to connect the pilot input to atmosphere.
The one or more penalty valves may be connected to the pilot port of the first pilot valve via the first input of the magnetic valve or may be connected to the pilot port of the first pilot valve at the output of the magnetic valve. The penalty valves are responsive to an electric penalty signal or a pneumatic penalty signal. One or more of the penalty valves may be connected to the pilot port of the first pilot valve by a suppression or second pilot valve which selectively disconnects the penalty valve from the pilot port in response to a suppression signal. A pilot port of the second pilot valve may either be controlled by a second magnetic valve or by a pneumatic source of a suppression signal.
These and other aspects of the present invention will become apparent from the following detailed description of the invention, when considered in conjunction with accompanying drawings.